Cementing and floating device for well casings



Sept. l5, 1931. R. c. BAKER 1,823,312

CEMENTING AND FLOATING DEVICE Fon WELL cAsINGs Filed July 13.v 1929 F u. Z.

Patented sept'. 15, 1931 UNITED STATES REUBEN C. BAKER, F COALINGA, CALIFORNIA CEMENTING AND FLOATING DEVICE FOR WELL CASINGS Application mea Ju1y 13, 1929.

This invention relates to oil well floating and cement-ing shoes and collars of the type disclosed in my prior application entitled Guiding, floating and cementing shoe filed November 23, 1927, Serial Number 235,204,

which may be produced by the method disclosed in my prior application entitled Method and mold for producing guiding, fioating and cementing shoes filed November 23, 1927, Serial Number 235,205.

It is the principal object of the present i11- vention to provide a device of the character disclosed in these prior applications wherein a single passageway of comparatively small area is formed longitudinally through the plug, which passageway is controlled by a back pressure valve of the ball type which permits fluid to be discharged outwardly ythrough the plug but is effective in preventing the passage of fluid through the plug into the casing.

In carrying out this object into practice, I provide either a well casing collar or a casing shoe and cast a cementitious plug therein.

This plug is formed with a central valve chamber from opposite ends of which extends a comparatively small passageway both through the upper and lower ends of the plug. A ball Valve is arranged in the chamber,

which valve isf/buoyant and is adapted to cooperate with a valve seat at the upper end of the valve chamber so as to prevent the passage of fluid upwardly through the plug. Means are provided, howeverffor preventing the ball valve from seating at the lower end of the valve chamber so that fluid may be forced downwardly through the plug.

`One form which the invention may assume is exemplified in the following description '0 and illustrated by way of example in the accompanying drawings, in which Fig. 1 is a perspective View in central section through a cementing and floating shoe embodying the preferred form of my inven- Fig. 2 is a similar view through what I prefer to term a float collar.

Fig. 3 is a transverse sectional view through the device taken on line lll-III of Fig. 1.

Serial No. 377,961.

Fig. 4 is an end view of the device.

Referring more particularly to the accompanying' drawings, in Fig. 1 I illustrate a casing shoe l0 which is cylindrical,and within which a cementitious plug 11 is cast. Grooves 12 are formed in the interior surface of the casing shoe 10 so that interlocking connections will be formed between the plug 11 and the casing shoe so as to prevent dislodgment of the plug by pressure applied to either end thereof.

Formed in the plug is a valve chamber 14, the upper end of which is defined by a flat disc 15, preferably of bakelite or other similar non-metallic but friable'material. The lower end of the chamber is defined by a concave disc 16 which is likewise formed of bakelite or similar non-metallic material. Extending between these two discs 15 and 16 is a cylinder 17, also of non-metallic material, the ends of which project within grooves formed in the adjacent surfaces of the discs 15 and 16.

It will be noticed that the peripheral edges of the discs 15 and 16 are imbedded within the cementitious body portion of the plug 12.

A passageway 18 is formed from the upper end of the valve chamber 18 through the upper end of the plug co-axially of the latter. This passageway is of comparatively small area and a valve seat 19 is formed at its lower end where it extends into the chamber through the upper disc 15. A similar passageway 20 is formed from the lower end of the chamber 14, through the lower end of the plug. This passageway preferably in alignment with the passageway 18.

A ball valve 21 is arranged in the valve .chamber 14 for cooperation with the valve seat 19. This ball valve 2l is in reality a back pressure valve and is preferably buoyant in such fluid as hydrauli(l cement so that when vthe pressure enters into the valve chamber from the passageway 2l), the ball valve 2l will rise and seat on the seat l!) and prevent the passage of fluid upwardly through the passageway 1S.

In order that fluid nary' be forced downwardly through the passageway 1S. valve 'lumilvor ll and lllc passageway 20. @UL Of theplugthe ball valve 21 is prevented from obstructing the passageway 20. This is accomplished by the provision of radially arranged and spaced'lugs 22 which are formed integrally with the lower disc 16 and project upwardly into the valve chamber. The disposition of these lugs 22 is such that the ball valve 21 will bear thereon and be supported at a distance above the junction between the passageway 20 and the valve chamber 14, enabling Huid to pass downwardly through the valve chamber and through the passageway 20 into the hole.

I produce this plug preferably by the method claimed in my prior application entitled Method and mold for producing guiding, floating and cementing shoes filed November 23, 1927, Serial Number 235,205. In accordance with this method, the casing shoe or collar 10 is fitted into the upper end of a mold.` The discs 15 and 16 and the cylinder 17 with the ball valve arranged therein, are supported on a core structure for coring the passageways 18 and 20. The core structure and the valve chamber are then filled with sand and the cementitious material is inserted into the shoe around the core structure. WVhen the cement is hardened, the core structure and sand is washed out of thevplug, leaving thel discs 15 and 16, the cylinder 17 and the ball valve 21 in proper, position within the shoe. As the peripheral edges ofthe discs 15 and 16 project beyond the outer periphery of the cylinder 17 their marginswill beimbedded wlithin the cementitious body portion of the ug s p v y y In Fig. 2 I'have disclosed afloat collar embodying the same invention as that shown in Fig. 1', and produced by the same method, the only difference in `the two structures being that in Fig. 2 the cementitious plug is cast within' a casing collar so that it may be interposed between lengths of vcasing in a well string.

In Fig. lfthe plug is shown formed in a casing shoe which'is fitted at the lower extremity of a Well casing.

In operation, the device is fitted in proper position on the well string` While the string is being lowered in the hole, fluid pressure will be upwardly through the passageway 20 and will cause the ball valve 21 to seat on the seat 19, thus preventing the flow of fluid upwardly into the casing, and enabling the casing to be floatedinto place. After the casing has been lowered to position, if it is desired to cement through the plugs, cement is forced downwardly through the casing with sucient pressure to overcome the pressure exteriorly ofthe casing. This downward pressure .will cause the ball valve 21 to bear against the plugs 22, leaving a free passagewaylfor lcement, through the passageway 18, valve chamber 14'` and outwardly through the passageway'i-20. After" the cement has been ejected and the pressure inthe casing'relieved, the pressure eXteriorly of the plug" through the passageway 20. This will be accomplished by an upward movement of the ball valve 21 and the seating thereof on the seat 19. This, of course, will effectively prevent the re-entrance of cement into the well casing.

While I have shown the preferred form of my invention, it is to be understood that Various changes may be made therein by those skilled in the art without departing from the spirit of the invention, as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent 1s- 1. A device of the character described including acementitious plug, said plug having a valve chamber formed therein intermediate the ends thereof, non-metallic discs imbedded in said plug, and defining the ends of said valve chamber, an upper passageway formed from the upper end of said valve chamber through the upper end of the plug, a lower passageway in vertical alignment withthe upper passageway formed at the lower end of the valve chamber through thel Alower end of the plug said passageways forming a single central straight opening extending entirely through the plug, said upperv non-metallic member being formed with a valve seat in alignment with the upper passageway, a buoyant ball valve arranged in said valve chamber for cooperation with said valve seat to prevent the passage of fluid upwardly from said valve chamber through said up'per passageway, spaced lugs formed as an integral part of said lower non-metallic part projecting upwardly within the valve chamber and adapted to engage the ball valve f and maintain the same'space from` the lower end of the valve chamber around the lower pasageway without constricting the same s0 as to permit the passage of `fluid downwardly through the lower passage.

2. In combination with pre-formed cylindrical metallic member, a cementitious plugv cast directly therein and anchored thereto, said plug having a valve chamber formed therein intermediate the ends thereof, nonmetallic discs imbedded in'said plug,and de lining the endsy of said valve chamber, an upper passageway formed ,froml the upper. end of said valve chamber through `the upper end of the plug, a lowerzpassageway invertical alignment with the upper passageway formed at the lower endof said Valve cham-y ber through the lower'end of the plug said passageways forming a 'singlecentral straight opening extendingy entirely through the plug, said upperfnon-metallie member,130

being formed with a valve seat in alignment with the upper passageway, a buoyant ball valve arranged in said valve chamber for cooperation w1th said Valve seat to prevent the passage of Huid upwardly from said valve chamber through said upper passageway, spaced lugs formed as an integral part of said lower non-metallic part projecting u wardly within the Valve chamber around t e lower passageway without constricting the same and adapted to engage the ball valve and maintain the same spaced from the lower end of the Valve chamber so as to permit the passage of fluid downwardly through the lower passage.

REUBEN C. BAKER. 

